std::atomic<int> cnt = 0, sum = 0;
std::vector<int> data = {1, 2, 3, 4, 5, 6, 7, 8, 9};
std::for_each(std::execution::par_unseq,
	data.begin(), data.end(), 
	[&](int el) {
		cnt++;
		sum += el;
	});
// cnt == 9, sum == 45
